SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND PRACTICES - Schedule of Rollforward Goodwill (Detail) - USD ($) $ in Thousands			3 Months Ended	12 Months Ended
	Dec. 01, 2018	Dec. 01, 2017	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Balance at beginning of period				$ 284,804	$ 355,786
Foreign currency adjustments				(2,893)	4,259
Disposal				(261)
Impairment loss	$ 0	$ 0	$ (75,200)	0	(75,241)	$ 0
Balance at end of period				281,650	284,804	355,786
IHT
Goodwill [Roll Forward]
Balance at beginning of period				194,211	213,475
Foreign currency adjustments				(1,603)	1,876
Disposal				0
Impairment loss					(21,140)
Balance at end of period				192,608	194,211	213,475
MS
Goodwill [Roll Forward]
Balance at beginning of period				56,600	109,059
Foreign currency adjustments				(712)	1,642
Disposal				(261)
Impairment loss					(54,101)
Balance at end of period				55,627	56,600	109,059
Quest Integrity
Goodwill [Roll Forward]
Balance at beginning of period				33,993	33,252
Foreign currency adjustments				(578)	741
Disposal				0
Impairment loss					0
Balance at end of period				$ 33,415	$ 33,993	$ 33,252